Electrochemiluminescent (ECL) Aptasensor for Lysozyme Using a Graphene Quantum Dot (GQD)-Ruthenium Bipyridine-Silica Nanocomposite

Abstract

An electrochemiluminescent (ECL) aptasensor for lysozyme (Lyz) based on a graphene quantum dot (GQD)-ruthenium bipyridine (Ru(bpy)₃²⁺)-silica (GQDs-Ru(bpy)₃²⁺@SiO₂) nanocomposite were prepared by encapsulating GQDs and the luminophore Ru(bpy)₃²⁺ in silica nanospheres (SiO₂). The nanocomposite GQDs-Ru(bpy)₃²⁺@SiO₂ with uniform size exhibited a strong and reproducible ECL response. The nanoprobe (DNA-GQDs-Ru(bpy)₃²⁺@SiO₂) was obtained via amidation between GQDs-Ru(bpy)₃²⁺@SiO₂ and the complementary DNA sequence. The ECL platform was constructed by hybridization between the aptamer and the complementary strand DNA. The specific recognition between aptamer and the target lysozyme maintained the nanoprobe DNA-GQDs-Ru(bpy)₃²⁺@SiO₂ away from the electrode, which led to the decreasing ECL response. The aptasensor exhibited a linear relationship from 0.1 to 100 pg/mL with a detection limit of 1.7 × 10⁻¹¹mg/mL. This study provided a simple and sensitive analytical approach for lysozyme.

Keywords:

• Aptasensor
• electrochemiluminescence (ECL)
• graphene quantum dots (GQDs)
• lysozyme

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (No. 22264014) and Innovation and Entrepreneurship Training Program for college students of Hubei Minzu University (No. 202210517005).